In U.S. patent application Ser. No. 08/938,692 assigned to the assignee of the present invention, a closure panel hemming apparatus is disclosed that includes a lower support supporting a lower hemming die and an upper support, spaced from and mounted above the lower support and supporting an upper hemming die. The upper and lower supports are relatively vertically moveable for moving the dies toward and away from one another. At least one guide post interconnects the upper and lower supports and maintains alignment of the upper and lower supports, during movement thereof. A plurality of actuators of the ball screw or rack and pinion type are driveably connected to draw together the upper and lower supports, bringing the dies together for edge hemming preformed metal panels nested between the dies.
The disclosed hemming apparatus has significant cost and control benefits over conventional press style hemming machines, yet requires actuators having sufficient size to impart the required hemming tonnage.